KB
Kenneth Beesley
Tue, Dec 3, 2019 7:01 PM
Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
-
The bore is circular, so some kind of extruded circle would be appropriate
-
But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
-
The center of the bore rotates around a radius
-
Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
Thanks, Ken
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
1. The bore is circular, so some kind of extruded circle would be appropriate
2. But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
3. The center of the bore rotates around a radius
4. Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
Thanks, Ken
*******************************
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
CG
Clint Goss
Tue, Dec 3, 2019 7:08 PM
You may be interested in the Breath Flute project ... BreathFlute.com.
The bottom of the flue (windway) was initially modeled after various 19th
century recorders for which I have good measurements (available on-line).
After mulling over these, I found that there was a suitable function based
on ArcTAN() that fit those measurements quite well. So I created a curve
and rotated it around the bore of the instrument.
The Breath Flute project is open-source, so you can download the code and
find the appropriate section (I don't recall the details at the moment).
There is also a massive Developer's Guide, which I think has details of how
that was done ...
-- Clint Goss
FluteCast.com ... direct links to Native American flute resources
Goss.com http://www.goss.com/ ... index of all our web sites
On Tue, Dec 3, 2019 at 2:03 PM Kenneth Beesley krbeesley@gmail.com wrote:
Relative beginner question: Saxophone flared bell tube, curved and
graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that flares
from beginning to end over a range of angles. For the time being, I'm
assuming that
-
The bore is circular, so some kind of extruded circle would be
appropriate
-
But the bore flares (increases in diameter) exponentially from
beginning to end (it should be possible to specify the diameter of each
"section" as a function of the angle)
-
The center of the bore rotates around a radius
-
Also, I'm assuming that one would first model the bore as a kind of
solid curved graduated cylinder, and then model a larger-diameter "shell"
as another solid curved graduated cylinder (on the same radius), and then
just subtract/difference the bore from the shell to get a curved graduated
tube (like a saxophone bell). The walls of the tube should be the same
thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and
rotate_extrude. rotate_extrude would seem to be perfect IF it offered
(like linear_extrude) the possibility of specifying the scale as an
interpolated function. I also just looked at ring_extrude, which seems
promising, except that the shape to be extruded must be specified as a
vector of points---it would be nice if one could simply extrude a simple
circle.
Are there any available functions that might help me model a saxophone
bell? Is there any better way to go about it?
Thanks, Ken
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
You may be interested in the Breath Flute project ... BreathFlute.com.
The bottom of the flue (windway) was initially modeled after various 19th
century recorders for which I have good measurements (available on-line).
After mulling over these, I found that there was a suitable function based
on ArcTAN() that fit those measurements quite well. So I created a curve
and rotated it around the bore of the instrument.
The Breath Flute project is open-source, so you can download the code and
find the appropriate section (I don't recall the details at the moment).
There is also a massive Developer's Guide, which I think has details of how
that was done ...
-- Clint Goss
FluteCast.com ... direct links to Native American flute resources
Goss.com <http://www.goss.com/> ... index of all our web sites
On Tue, Dec 3, 2019 at 2:03 PM Kenneth Beesley <krbeesley@gmail.com> wrote:
> Relative beginner question: Saxophone flared bell tube, curved and
> graduated, how to model it?
>
> I'm trying to model a saxophone bell, which has a bore (hole) that flares
> from beginning to end over a range of angles. For the time being, I'm
> assuming that
> 1. The bore is circular, so some kind of extruded circle would be
> appropriate
> 2. But the bore flares (increases in diameter) exponentially from
> beginning to end (it should be possible to specify the diameter of each
> "section" as a function of the angle)
> 3. The center of the bore rotates around a radius
>
> 4. Also, I'm assuming that one would first model the bore as a kind of
> solid curved graduated cylinder, and then model a larger-diameter "shell"
> as another solid curved graduated cylinder (on the same radius), and then
> just subtract/difference the bore from the shell to get a curved graduated
> tube (like a saxophone bell). The walls of the tube should be the same
> thickness throughout the result.
>
> I'm a beginner, but I have some acquaintance with linear_extrude and
> rotate_extrude. rotate_extrude would seem to be perfect IF it offered
> (like linear_extrude) the possibility of specifying the scale as an
> interpolated function. I also just looked at ring_extrude, which seems
> promising, except that the shape to be extruded must be specified as a
> vector of points---it would be nice if one could simply extrude a simple
> circle.
>
> Are there any available functions that might help me model a saxophone
> bell? Is there any better way to go about it?
> Thanks, Ken
>
> *******************************
> Kenneth R. Beesley, D.Phil.
> PO Box 540475
> North Salt Lake UT 84054
> USA
>
>
>
>
>
>
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>
KB
Kenneth Beesley
Tue, Dec 3, 2019 7:11 PM
Many thanks for the pointer.
Ken
On 3Dec2019, at 12:08, Clint Goss clint@goss.com wrote:
You may be interested in the Breath Flute project ... BreathFlute.com.
The bottom of the flue (windway) was initially modeled after various 19th century recorders for which I have good measurements (available on-line). After mulling over these, I found that there was a suitable function based on ArcTAN() that fit those measurements quite well. So I created a curve and rotated it around the bore of the instrument.
The Breath Flute project is open-source, so you can download the code and find the appropriate section (I don't recall the details at the moment). There is also a massive Developer's Guide, which I think has details of how that was done ...
-- Clint Goss
FluteCast.com http://flutecast.com/ ... direct links to Native American flute resources
Goss.com http://www.goss.com/ ... index of all our web sites
On Tue, Dec 3, 2019 at 2:03 PM Kenneth Beesley <krbeesley@gmail.com mailto:krbeesley@gmail.com> wrote:
Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
-
The bore is circular, so some kind of extruded circle would be appropriate
-
But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
-
The center of the bore rotates around a radius
-
Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
Thanks, Ken
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Discuss@lists.openscad.org mailto:Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
Many thanks for the pointer.
Ken
> On 3Dec2019, at 12:08, Clint Goss <clint@goss.com> wrote:
>
> You may be interested in the Breath Flute project ... BreathFlute.com.
>
> The bottom of the flue (windway) was initially modeled after various 19th century recorders for which I have good measurements (available on-line). After mulling over these, I found that there was a suitable function based on ArcTAN() that fit those measurements quite well. So I created a curve and rotated it around the bore of the instrument.
>
> The Breath Flute project is open-source, so you can download the code and find the appropriate section (I don't recall the details at the moment). There is also a massive Developer's Guide, which I think has details of how that was done ...
>
> -- Clint Goss
> FluteCast.com <http://flutecast.com/> ... direct links to Native American flute resources
> Goss.com <http://www.goss.com/> ... index of all our web sites
>
>
> On Tue, Dec 3, 2019 at 2:03 PM Kenneth Beesley <krbeesley@gmail.com <mailto:krbeesley@gmail.com>> wrote:
> Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
>
> I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
> 1. The bore is circular, so some kind of extruded circle would be appropriate
> 2. But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
> 3. The center of the bore rotates around a radius
>
> 4. Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
>
> I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
>
> Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
> Thanks, Ken
>
> *******************************
> Kenneth R. Beesley, D.Phil.
> PO Box 540475
> North Salt Lake UT 84054
> USA
>
>
>
>
>
>
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org <mailto:Discuss@lists.openscad.org>
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
*******************************
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
AC
A. Craig West
Tue, Dec 3, 2019 7:12 PM
I believe that a saxophone, of the majority of it's length, is linear,
and only goes non-linear at the very end of the bell
On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley krbeesley@gmail.com wrote:
Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
-
The bore is circular, so some kind of extruded circle would be appropriate
-
But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
-
The center of the bore rotates around a radius
-
Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
Thanks, Ken
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
I believe that a saxophone, of the majority of it's length, is linear,
and only goes non-linear at the very end of the bell
On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley <krbeesley@gmail.com> wrote:
>
> Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
>
> I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
> 1. The bore is circular, so some kind of extruded circle would be appropriate
> 2. But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
> 3. The center of the bore rotates around a radius
>
> 4. Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
>
> I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
>
> Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
> Thanks, Ken
>
> *******************************
> Kenneth R. Beesley, D.Phil.
> PO Box 540475
> North Salt Lake UT 84054
> USA
>
>
>
>
>
>
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
KB
Kenneth Beesley
Tue, Dec 3, 2019 7:25 PM
Thanks for the reply. Yes, the neck, body, bow, and perhaps part of the bell, graduate in bore diameter
pretty linearly, but the bell flares non-linearly. I’m doing some measurements now, and hope to
be able to discover the formula that describes the flaring.
I’ve cobbled together my own method of modeling curved, graduated tubes, essentially by unioning
a lot of cylindrical disks together, each one increasing a bit in size from the previous one. I was hoping that
there might be something like rotate_extrude, but with the possibility of designating the scaling as
an interpolated function.
Best,
Ken
On 3Dec2019, at 12:12, A. Craig West acraigwest@gmail.com wrote:
I believe that a saxophone, of the majority of it's length, is linear,
and only goes non-linear at the very end of the bell
On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley krbeesley@gmail.com wrote:
Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
-
The bore is circular, so some kind of extruded circle would be appropriate
-
But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
-
The center of the bore rotates around a radius
-
Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
Thanks, Ken
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
Thanks for the reply. Yes, the neck, body, bow, and perhaps part of the bell, graduate in bore diameter
pretty linearly, but the bell flares non-linearly. I’m doing some measurements now, and hope to
be able to discover the formula that describes the flaring.
I’ve cobbled together my own method of modeling curved, graduated tubes, essentially by unioning
a lot of cylindrical disks together, each one increasing a bit in size from the previous one. I was hoping that
there might be something like rotate_extrude, but with the possibility of designating the scaling as
an interpolated function.
Best,
Ken
> On 3Dec2019, at 12:12, A. Craig West <acraigwest@gmail.com> wrote:
>
> I believe that a saxophone, of the majority of it's length, is linear,
> and only goes non-linear at the very end of the bell
>
> On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley <krbeesley@gmail.com> wrote:
>>
>> Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
>>
>> I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
>> 1. The bore is circular, so some kind of extruded circle would be appropriate
>> 2. But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
>> 3. The center of the bore rotates around a radius
>>
>> 4. Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
>>
>> I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
>>
>> Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
>> Thanks, Ken
>>
>> *******************************
>> Kenneth R. Beesley, D.Phil.
>> PO Box 540475
>> North Salt Lake UT 84054
>> USA
>>
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> OpenSCAD mailing list
>> Discuss@lists.openscad.org
>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
*******************************
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
AC
A. Craig West
Tue, Dec 3, 2019 7:52 PM
I did write a method of extruding a polygon along a bezier path, that could
probably be slightly modified for non-linear scaling. I've been meaning to
put the code into shape to be posted publicly...
On Tue, 3 Dec 2019, 14:26 Kenneth Beesley, krbeesley@gmail.com wrote:
Thanks for the reply. Yes, the neck, body, bow, and perhaps part of the
bell, graduate in bore diameter
pretty linearly, but the bell flares non-linearly. I’m doing some
measurements now, and hope to
be able to discover the formula that describes the flaring.
I’ve cobbled together my own method of modeling curved, graduated tubes,
essentially by unioning
a lot of cylindrical disks together, each one increasing a bit in size
from the previous one. I was hoping that
there might be something like rotate_extrude, but with the possibility of
designating the scaling as
an interpolated function.
Best,
Ken
On 3Dec2019, at 12:12, A. Craig West acraigwest@gmail.com wrote:
I believe that a saxophone, of the majority of it's length, is linear,
and only goes non-linear at the very end of the bell
On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley krbeesley@gmail.com
wrote:
Relative beginner question: Saxophone flared bell tube, curved and
graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that flares
from beginning to end over a range of angles. For the time being, I'm
assuming that
-
The bore is circular, so some kind of extruded circle would be
appropriate
-
But the bore flares (increases in diameter) exponentially from
beginning to end (it should be possible to specify the diameter of each
"section" as a function of the angle)
-
The center of the bore rotates around a radius
-
Also, I'm assuming that one would first model the bore as a kind of
solid curved graduated cylinder, and then model a larger-diameter "shell"
as another solid curved graduated cylinder (on the same radius), and then
just subtract/difference the bore from the shell to get a curved graduated
tube (like a saxophone bell). The walls of the tube should be the same
thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and
rotate_extrude. rotate_extrude would seem to be perfect IF it offered
(like linear_extrude) the possibility of specifying the scale as an
interpolated function. I also just looked at ring_extrude, which seems
promising, except that the shape to be extruded must be specified as a
vector of points---it would be nice if one could simply extrude a simple
circle.
Are there any available functions that might help me model a saxophone
bell? Is there any better way to go about it?
Thanks, Ken
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
I did write a method of extruding a polygon along a bezier path, that could
probably be slightly modified for non-linear scaling. I've been meaning to
put the code into shape to be posted publicly...
On Tue, 3 Dec 2019, 14:26 Kenneth Beesley, <krbeesley@gmail.com> wrote:
> Thanks for the reply. Yes, the neck, body, bow, and perhaps part of the
> bell, graduate in bore diameter
> pretty linearly, but the bell flares non-linearly. I’m doing some
> measurements now, and hope to
> be able to discover the formula that describes the flaring.
>
> I’ve cobbled together my own method of modeling curved, graduated tubes,
> essentially by unioning
> a lot of cylindrical disks together, each one increasing a bit in size
> from the previous one. I was hoping that
> there might be something like rotate_extrude, but with the possibility of
> designating the scaling as
> an interpolated function.
>
> Best,
>
> Ken
>
> On 3Dec2019, at 12:12, A. Craig West <acraigwest@gmail.com> wrote:
>
> I believe that a saxophone, of the majority of it's length, is linear,
> and only goes non-linear at the very end of the bell
>
> On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley <krbeesley@gmail.com>
> wrote:
>
>
> Relative beginner question: Saxophone flared bell tube, curved and
> graduated, how to model it?
>
> I'm trying to model a saxophone bell, which has a bore (hole) that flares
> from beginning to end over a range of angles. For the time being, I'm
> assuming that
> 1. The bore is circular, so some kind of extruded circle would be
> appropriate
> 2. But the bore flares (increases in diameter) exponentially from
> beginning to end (it should be possible to specify the diameter of each
> "section" as a function of the angle)
> 3. The center of the bore rotates around a radius
>
> 4. Also, I'm assuming that one would first model the bore as a kind of
> solid curved graduated cylinder, and then model a larger-diameter "shell"
> as another solid curved graduated cylinder (on the same radius), and then
> just subtract/difference the bore from the shell to get a curved graduated
> tube (like a saxophone bell). The walls of the tube should be the same
> thickness throughout the result.
>
> I'm a beginner, but I have some acquaintance with linear_extrude and
> rotate_extrude. rotate_extrude would seem to be perfect IF it offered
> (like linear_extrude) the possibility of specifying the scale as an
> interpolated function. I also just looked at ring_extrude, which seems
> promising, except that the shape to be extruded must be specified as a
> vector of points---it would be nice if one could simply extrude a simple
> circle.
>
> Are there any available functions that might help me model a saxophone
> bell? Is there any better way to go about it?
> Thanks, Ken
>
> *******************************
> Kenneth R. Beesley, D.Phil.
> PO Box 540475
> North Salt Lake UT 84054
> USA
>
>
>
>
>
>
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>
>
>
> *******************************
> Kenneth R. Beesley, D.Phil.
> PO Box 540475
> North Salt Lake UT 84054
> USA
>
>
>
>
>
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>
KB
Kenneth Beesley
Tue, Dec 3, 2019 8:22 PM
Please keep me informed if your code gets posted.
Thanks,
Ken
On 3Dec2019, at 12:52, A. Craig West acraigwest@gmail.com wrote:
I did write a method of extruding a polygon along a bezier path, that could probably be slightly modified for non-linear scaling. I've been meaning to put the code into shape to be posted publicly...
On Tue, 3 Dec 2019, 14:26 Kenneth Beesley, <krbeesley@gmail.com mailto:krbeesley@gmail.com> wrote:
Thanks for the reply. Yes, the neck, body, bow, and perhaps part of the bell, graduate in bore diameter
pretty linearly, but the bell flares non-linearly. I’m doing some measurements now, and hope to
be able to discover the formula that describes the flaring.
I’ve cobbled together my own method of modeling curved, graduated tubes, essentially by unioning
a lot of cylindrical disks together, each one increasing a bit in size from the previous one. I was hoping that
there might be something like rotate_extrude, but with the possibility of designating the scaling as
an interpolated function.
Best,
Ken
Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
-
The bore is circular, so some kind of extruded circle would be appropriate
-
But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
-
The center of the bore rotates around a radius
-
Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
Thanks, Ken
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Discuss@lists.openscad.org mailto:Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
Please keep me informed if your code gets posted.
Thanks,
Ken
> On 3Dec2019, at 12:52, A. Craig West <acraigwest@gmail.com> wrote:
>
> I did write a method of extruding a polygon along a bezier path, that could probably be slightly modified for non-linear scaling. I've been meaning to put the code into shape to be posted publicly...
>
> On Tue, 3 Dec 2019, 14:26 Kenneth Beesley, <krbeesley@gmail.com <mailto:krbeesley@gmail.com>> wrote:
> Thanks for the reply. Yes, the neck, body, bow, and perhaps part of the bell, graduate in bore diameter
> pretty linearly, but the bell flares non-linearly. I’m doing some measurements now, and hope to
> be able to discover the formula that describes the flaring.
>
> I’ve cobbled together my own method of modeling curved, graduated tubes, essentially by unioning
> a lot of cylindrical disks together, each one increasing a bit in size from the previous one. I was hoping that
> there might be something like rotate_extrude, but with the possibility of designating the scaling as
> an interpolated function.
>
> Best,
>
> Ken
>
>> On 3Dec2019, at 12:12, A. Craig West <acraigwest@gmail.com <mailto:acraigwest@gmail.com>> wrote:
>>
>> I believe that a saxophone, of the majority of it's length, is linear,
>> and only goes non-linear at the very end of the bell
>>
>> On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley <krbeesley@gmail.com <mailto:krbeesley@gmail.com>> wrote:
>>>
>>> Relative beginner question: Saxophone flared bell tube, curved and graduated, how to model it?
>>>
>>> I'm trying to model a saxophone bell, which has a bore (hole) that flares from beginning to end over a range of angles. For the time being, I'm assuming that
>>> 1. The bore is circular, so some kind of extruded circle would be appropriate
>>> 2. But the bore flares (increases in diameter) exponentially from beginning to end (it should be possible to specify the diameter of each "section" as a function of the angle)
>>> 3. The center of the bore rotates around a radius
>>>
>>> 4. Also, I'm assuming that one would first model the bore as a kind of solid curved graduated cylinder, and then model a larger-diameter "shell" as another solid curved graduated cylinder (on the same radius), and then just subtract/difference the bore from the shell to get a curved graduated tube (like a saxophone bell). The walls of the tube should be the same thickness throughout the result.
>>>
>>> I'm a beginner, but I have some acquaintance with linear_extrude and rotate_extrude. rotate_extrude would seem to be perfect IF it offered (like linear_extrude) the possibility of specifying the scale as an interpolated function. I also just looked at ring_extrude, which seems promising, except that the shape to be extruded must be specified as a vector of points---it would be nice if one could simply extrude a simple circle.
>>>
>>> Are there any available functions that might help me model a saxophone bell? Is there any better way to go about it?
>>> Thanks, Ken
>>>
>>> *******************************
>>> Kenneth R. Beesley, D.Phil.
>>> PO Box 540475
>>> North Salt Lake UT 84054
>>> USA
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> OpenSCAD mailing list
>>> Discuss@lists.openscad.org <mailto:Discuss@lists.openscad.org>
>>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org>
>>
>> _______________________________________________
>> OpenSCAD mailing list
>> Discuss@lists.openscad.org <mailto:Discuss@lists.openscad.org>
>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org>
>
>
> *******************************
> Kenneth R. Beesley, D.Phil.
> PO Box 540475
> North Salt Lake UT 84054
> USA
>
>
>
>
>
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org <mailto:Discuss@lists.openscad.org>
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
*******************************
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
JB
Jordan Brown
Tue, Dec 3, 2019 9:40 PM
The advent calendar ( https://www.openscad.org/advent-calendar-2019/ )
has a candlestick (
https://files.openscad.org/advent-calendar-2019/01.scad ) that shows a
technique for rotate_extrude of a shape derived from a function.
It would be a little trickier to derive the coordinates for the inside
of the shape. It seems like you could take a curve's coordinates,
offset by epsilon in one direction or another, reverse it, combine to
form a very skinny curved polygon, then offset to form your final shape.
Here's the basic idea. I haven't tried to figure out the function you
would want.
$fa = 5;
$fs = 0.1;
function f(x) = log(x)*3;
minx = 2;
maxx = 5;
step = 0.1;
thickness = 0.5;
epsilon=0.001;
points = [
for (x = [minx:step:maxx]) [ x, f(x) ],
for (x = [maxx:-step:minx]) [ x+epsilon, f(x) ],
];
color("brown") rotate_extrude() offset(thickness/2) polygon(points);
The advent calendar ( https://www.openscad.org/advent-calendar-2019/ )
has a candlestick (
https://files.openscad.org/advent-calendar-2019/01.scad ) that shows a
technique for rotate_extrude of a shape derived from a function.
It would be a little trickier to derive the coordinates for the inside
of the shape. It seems like you could take a curve's coordinates,
offset by epsilon in one direction or another, reverse it, combine to
form a very skinny curved polygon, then offset to form your final shape.
Here's the basic idea. I haven't tried to figure out the function you
would want.
$fa = 5;
$fs = 0.1;
function f(x) = log(x)*3;
minx = 2;
maxx = 5;
step = 0.1;
thickness = 0.5;
epsilon=0.001;
points = [
for (x = [minx:step:maxx]) [ x, f(x) ],
for (x = [maxx:-step:minx]) [ x+epsilon, f(x) ],
];
color("brown") rotate_extrude() offset(thickness/2) polygon(points);
JB
Jordan Brown
Tue, Dec 3, 2019 9:53 PM
On 12/3/2019 1:40 PM, Jordan Brown wrote:
It would be a little trickier to derive the coordinates for the inside
of the shape. It seems like you could take a curve's coordinates,
offset by epsilon in one direction or another, reverse it, combine to
form a very skinny curved polygon, then offset to form your final shape.
Going back to the discussion of one-dimensional geometry, it would be
useful to be able to offset( ) a sequence of line segments, inflating
them to 2D.
(Perhaps a sequence of connected line segments is 1.5D.)
On 12/3/2019 1:40 PM, Jordan Brown wrote:
> It would be a little trickier to derive the coordinates for the inside
> of the shape. It seems like you could take a curve's coordinates,
> offset by epsilon in one direction or another, reverse it, combine to
> form a very skinny curved polygon, then offset to form your final shape.
Going back to the discussion of one-dimensional geometry, it would be
useful to be able to offset( ) a sequence of line segments, inflating
them to 2D.
(Perhaps a sequence of connected line segments is 1.5D.)
A
adrianv
Tue, Dec 3, 2019 11:14 PM
The list-comprehensions-demo library has a very general sweep command that
will connect a series of polygons with arbitrary transformations (scalings
and translations). There's also a skin operator that connects a set of
polygons.
https://github.com/RonaldoCMP/list-comprehension-demos
BOSL (and BOSL2) have extrusion of a shape along a path or bezier, and also
a skin operator.
https://github.com/revarbat/BOSL2/wiki
I think the dotSCAD library also supports some form of extrusion along a
path.
https://github.com/JustinSDK/dotSCAD
Note that all of these operations are based on a list of points. OpenSCAD
doesn't allow user functions to access geometry, so it is impossible to
write functions like that that use geometry directly.
Kenneth Beesley wrote
Please keep me informed if your code gets posted.
Thanks,
Ken
On 3Dec2019, at 12:52, A. Craig West <
I did write a method of extruding a polygon along a bezier path, that
could probably be slightly modified for non-linear scaling. I've been
meaning to put the code into shape to be posted publicly...
On Tue, 3 Dec 2019, 14:26 Kenneth Beesley, <
Thanks for the reply. Yes, the neck, body, bow, and perhaps part of the
bell, graduate in bore diameter
pretty linearly, but the bell flares non-linearly. I’m doing some
measurements now, and hope to
be able to discover the formula that describes the flaring.
I’ve cobbled together my own method of modeling curved, graduated tubes,
essentially by unioning
a lot of cylindrical disks together, each one increasing a bit in size
from the previous one. I was hoping that
there might be something like rotate_extrude, but with the possibility of
designating the scaling as
an interpolated function.
Best,
Ken
On 3Dec2019, at 12:12, A. Craig West <
I believe that a saxophone, of the majority of it's length, is linear,
and only goes non-linear at the very end of the bell
On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley <
Relative beginner question: Saxophone flared bell tube, curved and
graduated, how to model it?
I'm trying to model a saxophone bell, which has a bore (hole) that
flares from beginning to end over a range of angles. For the time
being, I'm assuming that
-
The bore is circular, so some kind of extruded circle would be
appropriate
-
But the bore flares (increases in diameter) exponentially from
beginning to end (it should be possible to specify the diameter of each
"section" as a function of the angle)
-
The center of the bore rotates around a radius
-
Also, I'm assuming that one would first model the bore as a kind of
solid curved graduated cylinder, and then model a larger-diameter
"shell" as another solid curved graduated cylinder (on the same
radius), and then just subtract/difference the bore from the shell to
get a curved graduated tube (like a saxophone bell). The walls of the
tube should be the same thickness throughout the result.
I'm a beginner, but I have some acquaintance with linear_extrude and
rotate_extrude. rotate_extrude would seem to be perfect IF it offered
(like linear_extrude) the possibility of specifying the scale as an
interpolated function. I also just looked at ring_extrude, which seems
promising, except that the shape to be extruded must be specified as a
vector of points---it would be nice if one could simply extrude a
simple circle.
Are there any available functions that might help me model a saxophone
bell? Is there any better way to go about it?
Thanks, Ken
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
Kenneth R. Beesley, D.Phil.
PO Box 540475
North Salt Lake UT 84054
USA
OpenSCAD mailing list
The list-comprehensions-demo library has a very general sweep command that
will connect a series of polygons with arbitrary transformations (scalings
and translations). There's also a skin operator that connects a set of
polygons.
https://github.com/RonaldoCMP/list-comprehension-demos
BOSL (and BOSL2) have extrusion of a shape along a path or bezier, and also
a skin operator.
https://github.com/revarbat/BOSL2/wiki
I think the dotSCAD library also supports some form of extrusion along a
path.
https://github.com/JustinSDK/dotSCAD
Note that all of these operations are based on a list of points. OpenSCAD
doesn't allow user functions to access geometry, so it is impossible to
write functions like that that use geometry directly.
Kenneth Beesley wrote
> Please keep me informed if your code gets posted.
>
> Thanks,
>
> Ken
>
>> On 3Dec2019, at 12:52, A. Craig West <
> acraigwest@
> > wrote:
>>
>> I did write a method of extruding a polygon along a bezier path, that
>> could probably be slightly modified for non-linear scaling. I've been
>> meaning to put the code into shape to be posted publicly...
>>
>> On Tue, 3 Dec 2019, 14:26 Kenneth Beesley, <
> krbeesley@
> <mailto:
> krbeesley@
> >> wrote:
>> Thanks for the reply. Yes, the neck, body, bow, and perhaps part of the
>> bell, graduate in bore diameter
>> pretty linearly, but the bell flares non-linearly. I’m doing some
>> measurements now, and hope to
>> be able to discover the formula that describes the flaring.
>>
>> I’ve cobbled together my own method of modeling curved, graduated tubes,
>> essentially by unioning
>> a lot of cylindrical disks together, each one increasing a bit in size
>> from the previous one. I was hoping that
>> there might be something like rotate_extrude, but with the possibility of
>> designating the scaling as
>> an interpolated function.
>>
>> Best,
>>
>> Ken
>>
>>> On 3Dec2019, at 12:12, A. Craig West <
> acraigwest@
> <mailto:
> acraigwest@
> >> wrote:
>>>
>>> I believe that a saxophone, of the majority of it's length, is linear,
>>> and only goes non-linear at the very end of the bell
>>>
>>> On Tue, Dec 3, 2019 at 2:02 PM Kenneth Beesley <
> krbeesley@
> <mailto:
> krbeesley@
> >> wrote:
>>>>
>>>> Relative beginner question: Saxophone flared bell tube, curved and
>>>> graduated, how to model it?
>>>>
>>>> I'm trying to model a saxophone bell, which has a bore (hole) that
>>>> flares from beginning to end over a range of angles. For the time
>>>> being, I'm assuming that
>>>> 1. The bore is circular, so some kind of extruded circle would be
>>>> appropriate
>>>> 2. But the bore flares (increases in diameter) exponentially from
>>>> beginning to end (it should be possible to specify the diameter of each
>>>> "section" as a function of the angle)
>>>> 3. The center of the bore rotates around a radius
>>>>
>>>> 4. Also, I'm assuming that one would first model the bore as a kind of
>>>> solid curved graduated cylinder, and then model a larger-diameter
>>>> "shell" as another solid curved graduated cylinder (on the same
>>>> radius), and then just subtract/difference the bore from the shell to
>>>> get a curved graduated tube (like a saxophone bell). The walls of the
>>>> tube should be the same thickness throughout the result.
>>>>
>>>> I'm a beginner, but I have some acquaintance with linear_extrude and
>>>> rotate_extrude. rotate_extrude would seem to be perfect IF it offered
>>>> (like linear_extrude) the possibility of specifying the scale as an
>>>> interpolated function. I also just looked at ring_extrude, which seems
>>>> promising, except that the shape to be extruded must be specified as a
>>>> vector of points---it would be nice if one could simply extrude a
>>>> simple circle.
>>>>
>>>> Are there any available functions that might help me model a saxophone
>>>> bell? Is there any better way to go about it?
>>>> Thanks, Ken
>>>>
>>>> *******************************
>>>> Kenneth R. Beesley, D.Phil.
>>>> PO Box 540475
>>>> North Salt Lake UT 84054
>>>> USA
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> OpenSCAD mailing list
>>>>
> Discuss@.openscad
> <mailto:
> Discuss@.openscad
> >
>>>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>>>> <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org>
>>>
>>> _______________________________________________
>>> OpenSCAD mailing list
>>>
> Discuss@.openscad
> <mailto:
> Discuss@.openscad
> >
>>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>>> <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org>
>>
>>
>> *******************************
>> Kenneth R. Beesley, D.Phil.
>> PO Box 540475
>> North Salt Lake UT 84054
>> USA
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> OpenSCAD mailing list
>>
> Discuss@.openscad
> <mailto:
> Discuss@.openscad
> >
>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>> <http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org>
>> _______________________________________________
>> OpenSCAD mailing list
>>
> Discuss@.openscad
>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>
>
> *******************************
> Kenneth R. Beesley, D.Phil.
> PO Box 540475
> North Salt Lake UT 84054
> USA
>
>
>
>
>
>
>
> _______________________________________________
> OpenSCAD mailing list
> Discuss@.openscad
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
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